[heap] Unify the immortal immovable root detection mechanism.

[heap] Unify the immortal immovable root detection mechanism.

Uniformly use the Heap::GetRootListIndex() and
Heap::RootIsImmortalImmovable() methods to detect immortal immovable
roots in the optimizing compilers.

R=jarin@chromium.org

Committed: https://crrev.com/84e83da99a72edc169367bf88588b1a2f10c2e08
Cr-Commit-Position: refs/heads/master@{#28933}

[Benedikt Meurer, 2015-06-11 08:24:17]

Hey Jaro,

This is cleanup for the immortal immovable root stuff. The adhoc macro solution
from Crankshaft is gone, and we use the same functions for both TurboFan and
Crankshaft now.
Please take a look.

Thanks,
Benedikt

[Jarin, 2015-06-11 09:17:06]

lgtm

[Benedikt Meurer, 2015-06-11 09:17:17]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-06-11 09:17:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1178853002/20001

[Benedikt Meurer, 2015-06-11 09:40:03]

The CQ bit was unchecked by bmeurer@chromium.org

[Benedikt Meurer, 2015-06-11 09:46:56]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-06-11 09:46:57]

The patchset sent to the CQ was uploaded after l-g-t-m from jarin@chromium.org
Link to the patchset: https://codereview.chromium.org/1178853002/#ps40001
(title: "Use the right predicate during code generation.")

[commit-bot: I haz the power, 2015-06-11 09:47:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1178853002/40001

[commit-bot: I haz the power, 2015-06-11 10:12:38]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-06-11 10:12:47]

Patchset 3 (id:??) landed as
https://crrev.com/84e83da99a72edc169367bf88588b1a2f10c2e08
Cr-Commit-Position: refs/heads/master@{#28933}

[Michael Achenbach, 2015-06-11 10:49:09]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/1178083003/ by machenbach@chromium.org.

The reason for reverting is: [Sheriff] tsan failures:
http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/4240.